So im trying to get my Z to the track before Thanksgiving, and i found out yesterday that the car has a 2 step set at 4000, i thought that button was my line lok. But i was gonna launch a few times in my driveway to check scrubing and all and found it. So has anyone ever used it. When i press the button it stutters at 4000, but while its doin that it smokes like crazy. When i let off it revs fine tho. Is that how its supose to work? Now i gotta find my line lok button....lol